2018 BMW X3: Real-World Fuel Economy

CARS.COM — The fuel-efficient 2018 BMW X3 gets an EPA-estimated 22/29/25 mpg city/highway/combined with its base engine, and I hit the highway mark on the dot after hundreds of miles across northern Illinois. And that’s despite adverse weather and passenger conditions (i.e., baby on board).

Related: 2018 BMW X3 Preview

BMW’s redesigned SUV won’t hit dealerships until November, but I logged 357.3 miles in an xDrive30i test car. The nomenclature signals the X3’s mainstream drivetrain, a turbo 2.0-liter four-cylinder with all-wheel drive and an eight-speed automatic transmission.

The trip was almost entirely highway miles, taking my family (two adults and a 3-month-old, plus a few weekend bags and a heavy stroller) west from the Chicago suburbs to northwest Illinois, then back east two days later. Pro tip for other parents: Infants cry too often for podcasts. Go with music.

Temperatures were in the 60s on the outbound (west) trip and the 50s for the return (east) trip, but steady winds battered both legs, with headwinds or crosswinds from 4 mph to 15 mph along our route, according to data from Weather Underground. Most of the return trip had double-digit headwinds or crosswinds.

Yet at journey’s end, the X3’s trip computer read 29.0 mpg — exactly the X3’s EPA highway number — as I pulled back to the same gas pump where I’d filled up to start the trip. The tank took 12.813 gallons of premium gas, yielding a pump calculation of 27.89 mpg. Whether you take either gas mileage figure or an average of the two, which we’ve done for past mileage tests, it’s clear the X3’s highway mileage is easily attainable.

The EPA estimates for fuel economy are competitive, landing among all-wheel-drive versions of the 2018 Mercedes-Benz GLC300 (24 mpg combined) and Audi Q5 (25 mpg combined). They’re also well ahead of competitors like the Cadillac XT5 and Lexus RX 350, though both run fine on 87-octane unleaded; the Germans prefer premium fuel.

I drove the X3 as I normally would — no hypermiling or acceleration testing — with the climate control in fully automatic mode and cabin temperature set to the 60s or low 70s. I avoided cruise control, kept the windows and the moonroof closed, and for the most part left the drivetrain in Adaptive mode (out of Adaptive, Comfort, Sport and Eco Pro).

At that, the X3 is a comfortable cruiser. The suspension soaks up expansion joints and uneven sections of interstate pavement with aplomb; overall isolation at 80 mph is excellent. The automatic transmission lags on multigear kickdowns if you need concerted power to merge with faster traffic, but it answers the call for lesser oomph with smooth, judicious shifts. More than 4,500 pounds’ curb and occupant weight turned the X3’s turbo four-cylinder (248 horsepower, 258 pounds-feet of torque) into a modest powertrain, but it still tacked on highway speed with steady resolve.

That’s it for now. Stay tuned for a full review and more specs.